Лако-красочные материалы — производство

There exists great potential for the development of ‘macro composite’ assemblies for use as structural elements or members, in which adhesives could provide the stress transfer mechanism between the different constituent materials. Examples might include decking elements or roof members comprising steel and timber, for example. An interesting structural possibility has been investigated by Oxford Polytechnic within the ABCON Programme(13), in which a composite flooring assembly was developed by bonding particle board sheeting over the top flanges of cold-formed galvanised steel joists (Fig. 8.8). Considerable increases in bending stiffness and overall strength were realised when compared with the alternative use of conventional self-drilling, self-tapping, screws — even when employed at close spacings. Apart from the immediate benefit of enhanced stiffness and feeling of solidity, the development suggests

either that economies can be made (in particle board thickness or joist material) or else that much stronger, stiffer assemblies can be fabricated.

The concept of bonding skins to frames, as opposed to the use of discrete mechanical fasteners, represents an obvious application of adhesives in order to stiffen existing structural elements by introducing stressed skin or membrane action. This is really an extension of the composite flooring development described above which examined the bending performance of assemblies constructed with long bondlines. It is also analogous to the use of polyurethane adhesives for the direct glazing of car bodies which confers significant additional body stiffness (see Chapter 1). A number of possibilities exist in the construction industry, perhaps the most obvious being the bonding of wall panels to lightweight structural steel framing systems, and the bonding of cladding panels to curtain walling systems.